The role of the Streptococcus mutans glucosyltransferases in the sucrose-dependent attachment to smooth surfaces: essential role of the GtfC enzyme.
Previous results have indicated that the glucosyltransferase activities of mutans streptococci are required for sucrose-dependent colonization of tooth surfaces. We have constructed mutants of Streptococcus mutans GS5 that are altered in varying combinations of the three gtf genes present in this organism. A quantitative in vitro sucrose-dependent attachment system was used to demonstrate that the inactivation of the gtfC gene drastically reduced adherence to smooth surfaces. By contrast, inactivation of the gtfB gene resulted in a smaller, but significant, reduction in attachment while the gtfD mutant was only marginally affected. Furthermore, production of only the glucosyltransferase C enzyme allowed for attachment although at reduced levels compared to the wild-type organism. The results from reintroduction of single copies of each of the gtf genes into a mutant of strain GS5 lacking glucosyltransferase activity also demonstrated the crucial role of the glucosyltransferase C enzyme in colonization. These results suggest a unique role for the glucosyltransferase C enzyme in the sucrose-dependent colonization of tooth surfaces by S. mutans strains.
Tsumori
H
H
Department of Oral Biology, State University of New York, Buffalo, USA.
Kuramitsu
H
H
D001422:Bacterial Adhesion / Q000502:physiology*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D003001:Cloning, Molecular; D015870:Gene Expression; D005798:Genes, Bacterial; D005964:Glucosyltransferases / Q000235:genetics / Q000378:metabolism*; D013295:Streptococcus mutans / Q000201:enzymology* / Q000235:genetics / Q000502:physiology; D013395:Sucrose / Q000378:metabolism
D001426:Bacterial Proteins; D013395:Sucrose; D005964:Glucosyltransferases; C110463:glucosyltransferase C